Molecular detection of Ehrlichia canis and Anaplasma platys in dogs from municipality of Belém, State of Pará, Brazil

ABSTRACT: The occurrence of diseases transmitted by ticks in dogs is very frequent in Brazil, among these diseases we can highlight the ehrlichiosis and anaplasmosis, which are caused by Ehrlichia canis and Anaplasma platys, respectively. The objective of this study was to survey the occurrence of these pathogens in blood samples from domiciled and stray dogs from the city of Belém, Pará. Two hundred and seventy six dogs were sampled for convenience, and the DNA extracted from the blood of these animals was submitted to nested-PCR for research of E. canis and A. platys. E. canis DNA was detected in 39.4% (109/276) and A. platys DNA in 23.1% (64/276) of the samples, there was a statistically significant difference between the frequency of these agents (P<0.0001), and there was coinfection in 13.4% (37/276) of animals. The frequency of detection of these parasites was higher in stray dogs than in those domiciled for both E. canis (OR=2.84) and A. platys (OR=10.5). Considering the results, it was possible to conclude that E. canis and A. platys are present in the studied population, with stray dogs being more affected by these parasites.

摘要：蜱传疾病在巴西犬只中极为高发，其中以埃立克体病（ehrlichiosis）和无形体病（anaplasmosis）最为突出，二者分别由犬埃立克体（Ehrlichia canis）与血小板无形体（Anaplasma platys）引发。本研究旨在针对帕拉州贝伦市家养与流浪犬的血液样本，开展这两种病原体的流行情况调查。本研究采用方便抽样法共纳入276只受试犬，从其血液中提取的DNA经巢式聚合酶链式反应（nested-PCR）扩增检测，以筛查犬埃立克体与血小板无形体的核酸。结果显示，受试样本中犬埃立克体DNA的检出率为39.4%（109/276），血小板无形体DNA的检出率为23.1%（64/276）；两种病原体的检出频率存在统计学显著性差异（P<0.0001），且13.4%（37/276）的受试犬存在共感染情况。无论是犬埃立克体（优势比OR=2.84）还是血小板无形体（优势比OR=10.5），流浪犬的病原体检出率均高于家养犬。综合上述研究结果可知，本研究覆盖的犬只种群中存在犬埃立克体与血小板无形体感染，且流浪犬受这两种病原体的感染程度更高。